Dubbed OptimEyes the system recognises facial characteristics that discover a customer's gender and age in order to show relevant video adverts while they are waiting to pay for their petrol.

There is nothing new about the technology. Pilots of bill boards which could tell what gender you were carried out in London years ago, to an underwhelming response.

Simon Sugar, chief executive of Amscreen, the firm which sells the technology, admitted to The Grocer that the technology has improved and is more like something out of Minority Report.

Needless to say the roll out has miffed some privacy groups, with Big Brother Watch's Nick Pickles telling the Guardian that OptimEyes creates a "huge consent issue".

People needed to be told that if they walk into a supermarket, or a doctor's surgery or a law firm, that the CCTV camera in the corner is trying to find out who they are, he said.

As far as the Information Commissioner's Office is concerned, such equipment would have to be clearly marked and explained as a customer enters the shop. A similar rule already exists for CCTV cameras.

What will enable Tesco to run its scheme is that it is hardly Minority Report yet. The software only scans your face, to guess what sex you are, it is hardly able to tell who you are and pull up a list of products it might think you would like.

Otherwise all a service station is going to get are adverts for petrol, Kit-Kats, Twixes and cigarettes and you do not really need facial recognition software to tell you that.